Non-lactate-assimilating yeast for improving aerobic stability of silage

Abstract

A method for treating silage to enhance aerobic stability by inhibiting growth of yeast strains associated with spoilage of silage is disclosed. The method comprises treating silage or feed with a composition comprising killer yeast strains, or the antimicrobial components produced thereby. According to the invention, strains of Saccharomyces exiguus have been purified and isolated which are nontoxic, safe, do not assimilate lactate and which improve aerobic stability of silage, are disclosed. Portions of these strains have been sequenced to further characterize the invention.

What is claimed is:  
     
       1. A composition for use as a silage inoculant comprising: 
       a yeast strain selected from the group consisting of SE24, SE136, SE151, said yeast stains having ATCC accession numbers 74441, 74442, and 74443, respectively and a carrier.  
     
     
       2. The composition of  claim 1  wherein the composition contains from about 10 2  to about 10 12  viable organisms per gram. 
     
     
       3. The composition of  claim 1  wherein the composition contains from about 10 7  to about 10 10  viable organisms per gram. 
     
     
       4. The composition of  claim 1  wherein the composition contains from about 10 9  to about 10 10  viable organisms per gram. 
     
     
       5. The composition of  claim 1  wherein the carrier is a liquid. 
     
     
       6. The composition of  claim 1  wherein the carrier is a solid. 
     
     
       7. The composition of  claim 1  wherein said carrier is a solid carrier and is water soluble and selected from the group consisting of calcium carbonate, starch, and cellulose. 
     
     
       8. A method for treating animal fed or silage susceptible to the growth thereon of spoilage or organisms which comprises; 
       adding to said feed a yeast strain that produces antimicrobial factors that inhibit the growth of said spoilage organisms selected from the group consisting of SE24, SE136, SE151.  
     
     
       9. A method according to  claim 8 , wherein the silage is selected from the group consisting of grass, maize, alfalfa, wheat, legumes, sorghum, sunflower, and barley. 
     
     
       10. A method according to  claim 8 , wherein the inhibition of growth of spoilage organisms is added on ensiling. 
     
     
       11. A method according to  claim 8 , which comprises maintaining the silage for at least 30 days. 
     
     
       12. A method according to  claim 8 , wherein the silage is in an object or objects selected from the group consisting of a bale, an oxygen limiting bag, a bunker, a stave silo, oxygen limiting silos, bags, and piles. 
     
     
       13. A method according to  claim 8 , which comprises adding to the feed or silage a microorganism having the ability to produce antimicrobial factors that inhibit the growth of spoilage organisms on fermentation. 
     
     
       14. The method of  claim 13  wherein said microorganism is  Saccharomyces exiguus  strain SE24 having ATCC accession number 74441. 
     
     
       15. The method of  claim 13  wherein said microorganism is  Saccharomyces exiguus  strain SE136 having ATCC accession number 74442. 
     
     
       16. The method of  claim 13  wherein said microorganism is  Saccharomyces exiguus  strain SE151 having ATCC accession number 74443. 
     
     
       17. A composition produced by the method of  claim 8 . 
     
     
       18. Animal feed to which has been added a yeast strain in accordance with the method of  claim 8 . 
     
     
       19. Animal feed to which has been added a microorganism in accordance with the method of  claim 13 . 
     
     
       20. Silage to which has been added a yeast strain in accordance with the method of  claim 8 . 
     
     
       21. Silage to which has been added a microorganism in accordance with the method of  claim 13 .